build: Show a warning if the system bus socket is not interoperable

We would like to start using ${runstatedir}/dbus/system_bus_socket,
so that distributors who make /var/run a symbolic link to /run will
usually get their dbus-daemon listening on /run/dbus/system_bus_socket,
which has some advantages in corner cases, such as when /var is mediated
by an automounter or is unmounted during system shutdown.

Unfortunately, the interoperable path in the D-Bus Specification is
/var/run/dbus/system_bus_socket for historical reasons (D-Bus is older
than /run), and older versions of Slackware are known to have had /run
and /var/run as distinct directories. Do a check during configuration
to catch systems configured like this and show a warning.

When cross-compiling, this assumes that the system where dbus is built
(the build system in Autotools/Meson, or the "host" in CMake terminology)
has its /var/run and /run set up in a way that is compatible with the
system where dbus will run (the host system in Autotools/Meson, or the
"target" in CMake terminology). This is not 100% correct, but seems good
enough for a warning that will hopefully only trigger for misguided OS
distributors.

Signed-off-by: Simon McVittie <smcv@collabora.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
index ae2d648d..81f3c91e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -37,6 +37,7 @@ EXTRA_DIST =			\
 	test/CMakeLists.txt \
 	test/name-test/CMakeLists.txt \
 	tools/CMakeLists.txt \
+	tools/check-runstatedir.sh \
 	cmake \
 	$(NULL)